Morse Taper Problem

[woodwish]

The original drive spur center that came with my lathe sticks like crazy and will pop out just like it should with needed to. I later bought a keyless drill chuck on a #2MT to hold some items like bottle stoppers and such. My problem is that no matter what I have tried I can not get the chuck to stay in the head stock. I can clean it, sand it, smack in with a rubber mallet, etc. but unless I keep the tail stock against the work it comes right out. Any suggestions to keep in place?

For example, today I was making a bunch of large maple Chirstmas ornaments that are shaped light those old large Christmas light bulbs. I would start with a block of maple and mount a 1/2" dowel in the end. I would put the dowel in the drill chuck to turn to shape and bring the tailstock up against up for support. After all but the end against the tailstock is turned & sanded I would part off the end, and then pull the tailstock back to sand the end where I just parted off. If I don't hold my hand or sandpaper against the end it will work it's way out and fly off the lathe. Does anyone know why this taper won't stay in place? (Yes it is a #2MT also).

Thanks, Ray

 

[kwgeorge]

For what it is worth I will tell you what I know about this subject. Morse Tapers are made to be used with constant pressure applied to them. They are not made to be used stand alone in your spindle and most of the accessories that I have that came with a #2 taper warn not to use them in the spindle without the tailstock applying pressure in the opposite direction. Some of the accessories have threads in the end of the taper so you can insert a threaded rod through the spindle to create a “draw bar†and these are safe to use in this manner.

 

[Erwin Nistler]

I have several #2 tapers that I have to beat out. However when using the screw center , on a #2 taper, if I turn away from the headstock it will work loose. As long as I turn toward the headstock it will not come out. Aparently the constant "taping" from the chisel will loosen it.

 

[-e-]

i've seen this problem, for example in the early jet mini's. the head stock taper was not machined deep enough forr some of the attachments ...

the threaded-rod is one fix -- or using shorter mts.

 

[Steve Worcester]

I would say, that when ever possible, if you are using a morse taper device without tailstock support, use a threaded rod.

Many of the mosre tapers intended for lathe use, have a threaded hole in the end. Take a piece of threaded rod, long enough to screw into the morse taper and stick out about a couple of inches out the other side of the headstock and make a wood plug with a nut on the end. Screw the whole assemble down when you want to use that morse taper device and it will not come out.
If it is not threaded, it can be quite easily as long as the tang (or end) is not hardened. If it is, you will have to anneal it to be able to drill and tap it.

 

[hockenbery]

wooden morse taper

The Draw bolt like Steve outlined is probably the best solution.

two other things are:
Try pressing the Jacobs chuck into the head stock by putting a scrap block between the Jacobs chuck and tailstock center and cranking a turn or two on the tailstock handwheel. The chuck should then hold better but vibration will probably lossen it eventually. Avoid too much presure since too much cranking pressure may damage the chuck or the lathe bearings.

Turn a wooden morse taper. These hold extremley well for turning small parts. Attach your block by Drilling a 1/2" diameter hole in the wooden taper to accept your 1/2" tennon and glue it with thick CA and accelorator.
the down side is you have to drill out the last tenon every time but you already have a jacobs chuck you can mount in the tailstock.

Happy turning,
Al

 

[Ken Grunke]

It could be the new taper shank is poorly machined, and maybe the taper is a bit off. Machinists check the fit of taper shanks by putting a thin stripe of blue dye paste lengthwise along the shank, putting it in the hole, and twisting it. If the whole line of dye is smudged, then the fit is correct. If not smudged on one end or the other, then the taper angle is wrong.
You could use a Sharpie permanent marker to draw a line on the shank, it should work for this.
First, I would look for any raised burrs on the shank, and file them off. If your original MT shank fits as it should, the socket in the spindle should be OK.

 

[Hawaii Turner]

What lathe?

What lathe do you have?
I had a similar problem with my Delta Midi Lathe. The cause was that the taper in the spindle wasn't machined sufficiently deep/or the clearance hole not drilled large or deep enough so that the small end of the taper shank "hung up" on a shoulder in the hole. My cure was to use a mt #2 taper shank 9/16" drill in the tailstock and drill the inside of the spindle about 1/8" deeper. Remember that this should be done at the lowest speed (500) if a belt drive lathe or if a VS, 450 rpm is better yet. A cutting oil should also be used. It worked for me.
Aloha
Doug :cool2:

 

[woodwish]

Bingo!! We have a winner!! It is a Delta Midi-lathe and after looking around in there it is exactly as you have described. I will look into your method of repair and see if that fixes it.

Thanks, Ray